1. Technical Field
The present invention relates to thin electro-optic apparatuses, electronic devices, and methods for manufacturing electro-optic apparatuses.
2. Related Art
The thin electro-optic apparatuses mentioned above include one disclosed in JP-A-2003-337322, a liquid crystal display having a liquid crystal panel made using a glass substrate thinner than 0.15 mm, a flexible printed circuit (FPC), a connector, and protection sheets that sandwich and combine other components while protecting them.
This liquid crystal display is energized by connecting the connector to an external apparatus equipped with a driver circuit.
Thin electro-optic apparatuses can be manufactured by methods including one disclosed in JP-A-2008-165219, polishing a silicon wafer to a thickness equal to or smaller than 100 μm and then bonding the obtained flexible driver IC onto a flexible display panel with or without an intervening FPC.
This publication lists some examples of the flexible display panel, such as liquid crystal displays, plasma displays, organic/inorganic EL (electroluminescence) displays, electrophoretic displays, and electrochromic displays.
As described above, the driver IC is bonded onto the flexible display panel by electric means; however, the use of the intervening FPC may possibly increase the output impedance, thereby reducing output signals, and this would affect display characteristics. It is desirable that the driver IC should be bonded directly onto the flexible display panel.
However, there are some problems with bonding a flexible driver IC directly onto the liquid crystal display according to JP-A-2003-337322. In so-called COG (chip-on-glass) bonding, in which a driver IC is bonded directly onto the terminal portion of a liquid crystal panel, the driver IC is polished to a thickness equal to or smaller than 100 μm in advance, and this reduced thickness makes it difficult to ensure the positional accuracy of bonding the driver IC onto a liquid crystal panel in plan view. Furthermore, such a thin driver IC should be handled with due care during bonding; otherwise, it may possibly be damaged.
COG bonding causes another problem later; protective sheets sandwich and combine the driver IC and other components, and thus the heat generated by the current flowing in the driver IC cannot be easily radiated.